diff --git a/requirements.txt b/requirements.txt
index 6589abe..f2e73ea 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -26,7 +26,7 @@ nltk==3.4.5
 numpy==1.16.4
 pandas==0.25.0
 prompt-toolkit==2.0.9
-protobuf==3.9.1
+protobuf==3.15.0
 py2neo==4.3.0
 Pygments==2.3.1
 PyMySQL==0.9.3